Table 71 



DETERMINATION OF HEIGHTS BY THE BAROMETER. 

 Formula of Babinet. 



Bo+B 



900 



— English Measures. 



z = c 



C (in feet) ^ 52494 |^i -f- 



C (in metres') = 16000 i 4 — ^ ' — Metric Measures. 



^ ' L 1000 J 



In which Z =; Difference of height of two stations in feet or metres. 



B^, B = Barometric readings at the lower and upper stations respectively, 

 corrected for all sources of instrumental error. 

 t^, t = Air temperatures at the lower and upper stations respectively. 



Values of C. 



ENGLISH MEASURES. 



METRIC MEASURES. 



Smithsonian Tables. 



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